The present invention relates to optical communication techniques. More particularly, the present invention provides an optical equalizer, a photonics system having the same, and a method of using thereof.
Equalizers are required to overcome the inter-symbol interference (ISI) generated by bandwidth limitations of electro-optical components for optical communication such as modulator or other impairments due to optical fiber such as chromatic dispersion and polarization mode dispersion.
Equalization in optical domain is advantageous over electrical domain as phase information is available in the optical domain. A few types of optical equalizers have been proposed based on optical finite impulse response (FIR) filters before, where some are limited to specific source of ISI in the transmitted signals and some need to be used at the receiver as the summation is done in electrical domain. Some other ones suffer poor performance due to thermal variation. Improved optical equalizer is desired and important for new generation photonics system used in electro-optical communication network.